1. Field of the Invention
This invention relates to diesel fuel and, more particularly, to a diesel fuel composition containing a detergent additive which actively cleans deposits from dirty diesel fuel injectors.
2. Description of Related Information
Diesel fuel impurities can arise from a variety of sources. They can form during refining or they can develop as a result of the oxidation which occurs during storage. Such impurities tend to be both soluble and insoluble materials having higher molecular weights and boiling points than the fuel, and which manifest themselves in the engine as colors or gums. Impurities can also be introduced into the fuel during handling or during storage from corrosion of storage vessels. Impurities can even take the form of other additives intentionally introduced by the manufacturer to solve or prevent some particular problem or improve the fuel itself, such as, for example, anti-oxidants, rust preventatives, etc.
Regardless of the source, any of these impurities can cause deposits to form in the fuel system of compression ignition engines, and, in particular, in the fuel injectors. These deposits coat or adhere to injector parts and cause injector sticking, injector tip fuel metering passage fouling, nozzle hole plugging, leakage past critical surfaces, and delayed injection (and, hence, delayed start of combustion). These problems, in turn, result in significantly increased engine noise, smoke emissions, misfiring, low temperature or cold start problems, and idle roughness, and decreased power output and fuel economy.
It is believed that these engine problems are the result of long ignition delays, significantly contributed to by deposits, causing an excessively rapid pressure rise in the cylinder once combustion does occur. Recent evidence suggests that the long delay provides the time for certain chemical reactions to take place in the atomized fuel charge prior to ignition, resulting in products which burn exceedingly rapidly once combustion begins, thereby causing the undesirable rapid pressure rise, and the resultant problems.
It would therefore be desirable to prevent the deposits caused by impurities or to remove such deposits once they have formed. The present invention provides a diesel fuel composition which contains a detergent additive which is effective to remove deposits from dirty diesel fuel injectors and to keep these injectors clean. These and other objects of the present invention are discussed in more detail below.